Method of controlling sounds generated in a hearing aid and a hearing aid

Abstract

A hearing aid ( 100 ) configured to control the generation of relaxing sound comprises an acoustical-electrical transducer ( 101 ), means ( 105 ) for deriving a characteristic value from the electrical audio signal, comparator means ( 106 ) configured to compare the derived characteristic value with a selected threshold value; relaxing sound generating means ( 108 ), first signal processing means ( 109 ) adapted for increasing or decreasing the level of the electrical relaxing sound signal as a function of the control value and a selected threshold value, means ( 102 ) for adding the processed electrical relaxing sound signal to the electrical audio signal, second signal processing means ( 103 ) configured to amplify the electrical input signal and an electrical-acoustical output transducer ( 104 ). The invention further provides a method of controlling the generation of relaxing sound in a hearing aid ( 100 ).

1 . A hearing aid configured to control the generation of relaxing sound comprising:
 an acoustical-electrical transducer adapted for converting an acoustical input sound into an electrical audio signal;   means for deriving a characteristic value from the electrical audio signal;   comparator means configured to compare the derived characteristic value with a selected threshold value hereby providing a control value;   switching means configured to select a first threshold value if the characteristic value drops below a second threshold value, while the second threshold value is selected, and to select the second threshold value if the characteristic value exceeds the first threshold value, while the first threshold value is selected, and wherein the second threshold value is smaller than the first threshold value;   relaxing sound generating means for providing an electrical relaxing sound signal;   first signal processing means adapted for increasing or decreasing the level of the electrical relaxing sound signal as a function of the control value and the selected threshold value, hereby providing a processed electrical relaxing sound signal;   means for adding the processed electrical relaxing sound signal to the electrical audio signal hereby providing an electrical input signal;   second signal processing means configured to amplify the electrical input signal in order to alleviate a hearing loss of a hearing aid user, hereby providing an electrical output signal; and   an electrical-acoustical output transducer for converting the electrical output signal into sound.   
     
     
         2 . The hearing aid according to  claim 1 , wherein the means for deriving a characteristic value estimates the sound pressure level of the acoustical input sound. 
     
     
         3 . The hearing aid according to  claim 1 , comprising means for detecting speech in the electrical audio signal and wherein the second signal processing means or the relaxing sound generating means are configured to mute the acoustical relaxing sound if speech is detected. 
     
     
         4 . The hearing aid according to  claim 1 , wherein the relaxing sound generating means comprise means for providing an electrical relaxing sound signal representing a consecutive set of tones with varying tonal characteristics. 
     
     
         5 . The hearing aid according to  claim 4 , wherein the relaxing sound generating means are configured to discontinue the generation of new tones while already generated tones are allowed to fade-out in response to a situation where the first characteristic value exceeds the first threshold value, while the first threshold value is selected. 
     
     
         6 . A method of controlling the generation of relaxing sound in a hearing aid, comprising the steps of:
 converting an acoustical input sound into an electrical audio signal;   deriving a first characteristic value from the electrical audio signal;   deriving a second characteristic value from the electrical audio signal;   determining a level of an electrical relaxing sound signal based on the first characteristic value and the second characteristic value; and   providing the acoustical relaxing sound with the determined level.   
     
     
         7 . The method according to  claim 6 , comprising the steps of:
 providing a first threshold value;   providing a second threshold value, wherein the second threshold value is smaller than the first threshold value;   deriving the first characteristic value at a first point in time;   deriving the second characteristic value at a second point in time, wherein the second point in time is later than the first point in time;   selecting the first threshold value if the first characteristic value drops below the second threshold value;   selecting the second threshold value if the first characteristic value exceeds the first threshold value;   decreasing the level of the electrical relaxing sound signal if the second characteristic value is greater than the first threshold value and the first threshold value is selected;   increasing the level of the electrical relaxing sound signal if the second characteristic value is smaller than the second threshold value and the second threshold value is selected.   
     
     
         8 . The method according to  claim 7 , comprising the step of:
 muting the acoustical relaxing sound in response to a positive value of a third characteristic value, wherein the third characteristic value is positive if speech is detected in the electrical audio signal, and negative if speech is not detected in the electrical audio signal.   
     
     
         9 . The method according to  claim 6 , wherein the first characteristic value and the second characteristic value are estimates of the input sound pressure level. 
     
     
         10 . The method according to  claim 9 , wherein the difference between the first threshold value and the second threshold value is in the range between  3  and  8  decibel SPL. 
     
     
         11 . The method according to  claim 9 , wherein the first threshold value corresponds to an estimated input sound pressure level that is in the range between 10 and 60 decibel SPL. 
     
     
         12 . The method according to  claim 7 , wherein the acoustical relaxing sound is muted if the first characteristic value exceeds the first threshold value. 
     
     
         13 . The method according to  claim 12 , wherein the muting of the acoustical relaxing sound is carried out by discontinuing the generation of new relaxing tones whereby the muting becomes more difficult to consciously perceive for a user of the hearing aid. 
     
     
         14 . The method according to  claim 13 , wherein existing relaxing tones will fade out during a time span in the range between 0.5 and 5 seconds after the generation of new relaxing tones has been discontinued. 
     
     
         15 . The method according to  claim 6 , comprising the steps of:
 determining the level of the electrical relaxing sound signal to correspond to the estimate of the input sound pressure level;   muting the acoustical relaxing sound in response to a positive value of the second characteristic value, wherein the second characteristic value is positive if speech is detected in the electrical audio signal and negative if speech is not detected in the electrical audio signal.   
     
     
         16 . The method according to  claim 6 , comprising the steps of:
 determining the level of the electrical relaxing sound signal to be oppositely directed with respect to the estimate of the input sound pressure level;   muting the acoustical relaxing sound in response to a positive value of the second characteristic value, wherein the second characteristic value is positive if speech is detected in the electrical audio signal and negative if speech is not detected in the electrical audio signal.   
     
     
         17 . The method according to  claim 8 , wherein the acoustical relaxing sound is muted less than 100 microseconds after speech has been detected. 
     
     
         18 . The method according to  claim 8 , wherein the level of the acoustical relaxing sound is gradually decreased to zero in a time span in the range between 1 and 20 milliseconds after speech has been detected.